Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion

Human walking parameters exhibit significant variability depending on the terrain, speed, and load. Assistive exoskeletons currently focus on the recognition of locomotion terrain, ignoring the identification of locomotion tasks, which are also essential for control strategies. The aim of this study...

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Main Authors: Yao Liu, Chunjie Chen, Zhuo Wang, Yongtang Tian, Sheng Wang, Yang Xiao, Fangliang Yang, Xinyu Wu
Format: Article
Language:English
Published: MDPI AG 2024-02-01
Series:Bioengineering
Subjects:
Online Access:https://www.mdpi.com/2306-5354/11/2/150
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author Yao Liu
Chunjie Chen
Zhuo Wang
Yongtang Tian
Sheng Wang
Yang Xiao
Fangliang Yang
Xinyu Wu
author_facet Yao Liu
Chunjie Chen
Zhuo Wang
Yongtang Tian
Sheng Wang
Yang Xiao
Fangliang Yang
Xinyu Wu
author_sort Yao Liu
collection DOAJ
description Human walking parameters exhibit significant variability depending on the terrain, speed, and load. Assistive exoskeletons currently focus on the recognition of locomotion terrain, ignoring the identification of locomotion tasks, which are also essential for control strategies. The aim of this study was to develop an interface for locomotion mode and task identification based on a neuromuscular–mechanical fusion algorithm. The modes of level and incline and tasks of speed and load were explored, and seven able-bodied participants were recruited. A continuous stream of assistive decisions supporting timely exoskeleton control was achieved according to the classification of locomotion. We investigated the optimal algorithm, feature set, window increment, window length, and robustness for precise identification and synchronization between exoskeleton assistive force and human limb movements (human–machine collaboration). The best recognition results were obtained when using a support vector machine, a root mean square/waveform length/acceleration feature set, a window length of 170, and a window increment of 20. The average identification accuracy reached 98.7% ± 1.3%. These results suggest that the surface electromyography–acceleration can be effectively used for locomotion mode and task identification. This study contributes to the development of locomotion mode and task recognition as well as exoskeleton control for seamless transitions.
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spelling doaj.art-3f147626ddc64c669d9e41d542acb6022024-02-23T15:07:57ZengMDPI AGBioengineering2306-53542024-02-0111215010.3390/bioengineering11020150Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical FusionYao Liu0Chunjie Chen1Zhuo Wang2Yongtang Tian3Sheng Wang4Yang Xiao5Fangliang Yang6Xinyu Wu7Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaShenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaShenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaShenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaGuangdong Provincial Key Lab of Robotics and Intelligent System, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaShenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaShenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaShenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, ChinaHuman walking parameters exhibit significant variability depending on the terrain, speed, and load. Assistive exoskeletons currently focus on the recognition of locomotion terrain, ignoring the identification of locomotion tasks, which are also essential for control strategies. The aim of this study was to develop an interface for locomotion mode and task identification based on a neuromuscular–mechanical fusion algorithm. The modes of level and incline and tasks of speed and load were explored, and seven able-bodied participants were recruited. A continuous stream of assistive decisions supporting timely exoskeleton control was achieved according to the classification of locomotion. We investigated the optimal algorithm, feature set, window increment, window length, and robustness for precise identification and synchronization between exoskeleton assistive force and human limb movements (human–machine collaboration). The best recognition results were obtained when using a support vector machine, a root mean square/waveform length/acceleration feature set, a window length of 170, and a window increment of 20. The average identification accuracy reached 98.7% ± 1.3%. These results suggest that the surface electromyography–acceleration can be effectively used for locomotion mode and task identification. This study contributes to the development of locomotion mode and task recognition as well as exoskeleton control for seamless transitions.https://www.mdpi.com/2306-5354/11/2/150assistive exoskeletonneuromuscular–mechanicallocomotion modes and taskshuman–machine collaboration
spellingShingle Yao Liu
Chunjie Chen
Zhuo Wang
Yongtang Tian
Sheng Wang
Yang Xiao
Fangliang Yang
Xinyu Wu
Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion
Bioengineering
assistive exoskeleton
neuromuscular–mechanical
locomotion modes and tasks
human–machine collaboration
title Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion
title_full Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion
title_fullStr Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion
title_full_unstemmed Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion
title_short Continuous Locomotion Mode and Task Identification for an Assistive Exoskeleton Based on Neuromuscular–Mechanical Fusion
title_sort continuous locomotion mode and task identification for an assistive exoskeleton based on neuromuscular mechanical fusion
topic assistive exoskeleton
neuromuscular–mechanical
locomotion modes and tasks
human–machine collaboration
url https://www.mdpi.com/2306-5354/11/2/150
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